1. Field of This Invention
This invention relates to a process for the preparation of transparent and weather-resistant vinyl chloride polymers having high impact strength by the polymerization of vinyl chloride either together with or without other copolymerizable monomers in aqueous dispersion by the emulsion polymerization method in the presence of acrylic ester copolymers (copolymerizates).
2. Prior Art
Belgian Pat. No. 770,011 discloses producing vinyl chloride polymers by the polymerization of vinyl chloride by the emulsion polymerization method in the presence of 2 to 10 percent by weight of a 2-ethyl hexyl acrylate polymer. In comparison with the products produced by previous prior art, these prior art products have increased impact strength and better transparency. These prior art products are suitable for the production of translucent products, but they have too much haze (as defined hereinafter) for use for transparent application. If higher transparency is required, the concentration of the 2-ethyl hexyl acrylate pre-polymer can be reduced or the diameter of the poly-2-ethyl hexyl acrylate particles can be reduced. Both these steps, however, reduce the impact strength.
See U.S. Pat. Nos. 2,894,950, 3,041,308, 3,041,309, 3,334,156, 3,426,101, 3,655,825, 3,692,871, 3,770,851 and 3,776,982. Also see Schildnecht, Calvin E., "Allyl Compounds and Their Polymers", Wiley Interscience, N.Y., (1973), pp. 602-603.